108 replies to this topic

[punkrock MX TT Titanium Member]

if i did that on my 250 2-stroke, it'd be dead quiet!

[PeteN TT Gold Member]

I rode the CRF150R with the 230F muffler on it last night and it was very impressive. Very quiet, about like my wife's stock 150F and still a little rocket! "Silent, but Deadly"!!

[airboy808 TT Bronze Member]

how quiet is it PeterN? I mean I know what a stock ttr125 and a stock crf50 sound like. is your crf150r with 230 muffler as quiet? if so, then I will be able to ride at night at our secret spot.

[Deilke53 TT Member]

Airboy, the bike Pete rode is mine...I wish I had some solid HP & dB numbers for everyone but I just haven't had a chance yet. It is very quiet, but because of the nature of the R motor, I think it must at least be a bit louder than my stock plugged 150F was but not much.
Anyway, stay tuned I'll have some real numbers hopefully before Xmas. For now, here is what the conversion looks like..

[BlackBuzzard TT Silver Member]

Nice pictures.

Is it stainless or mild steel on the inlet side of 230f muffer. Looks like some work was needed to make it fit right. I have a welder but can't do stainless with it.



BB

[Deilke53 TT Member]

Easily welded plain 'ol steel...and fairly thick too to make things extra easy.

[SEEKandDESTROY2 TT Bronze Member]

The muffler looks great man, nice work. do you have a video of you revving the bike up or riding it? I'm interesting in hearing how it sounds.
-Pete

[NMdesertRacer TT Addict]

Hey hows the testing coming along?

[Bearorso TT Newbie]

Hello People,

Deilke53 - what can I say other than you're a star!

I'm impressed by your commitment to making the bike quiet - Honda should be shot for making the 150R so loud - with the crazy advantage they have over an 85 a small amount of low end loss would not have affected the outcome of such an uneven match (mind you, for once AMA might have got it right with their 112cc 2t vs the 150f - a 112 2t will be a good match - here in OZ the MA just bent over for Honda & allowed the 150 to go against the 85s)

I just hope the other manufacturers have some sense & make their 150Fs quiet, as we all know the vast majority will be ridden by kids at anything but a closed course. Come to think of it, are any kids getting to ride these little monsters - seems to be more adults on these things than kids:eek:

Once again, great work:worthy:

Bearorso

[Hondaracing915g TT Gold Member]

Awesome post can't believe you were able to dorp it 10 decibals...put that pipe into production for the 150R.

[Deilke53 TT Member]

Hello again, and thanks for the new compliments. Wish I had more exhaust progress to to report but since the 230f muffler was installed, the bike has been exactly the kind of quiet that I needed/wanted it to be for my riding situation..so the sound issue has slipped off the front burners for a while.

I did get a chance make a few quick runs with the 230f muffler a few weeks ago...the same dyno that recorded 19.6 peak hp with the stock muffler, says the peak is 17.4hp @ 11K, and it begins a steady decline from 11K to about 14hp @ the rev limiter. So for now, the cost of being ultra quiet is the mostly some power at the top end of the rev range (which I doubt I'll really miss) and a bit of the excessive wheelspin at the bottom end, which my gravel driveway certainly won't miss:) and upshifting at 12K or so might extend the motor'ds life a bit. I'm sure many TTalkers won't like the idea of giving up 2+ hp, but I'm completely satisfied for now with its current balance of power delivery and noise. As an all purpose, tractable, damn snappy adult playbike..it's at least as good specs-wise as any dreamy 150F/CR85 hybrid I could have built last year, just much much quieter and less expensive.

Anyway, glad to hear that some of you are using the DbDawg product etc to at least tone these things down a bit. I've heard rumor that BBR is working on a "quiet" pipe..if true, I hope they're using a stock plugged minibike as the sound level goal and then trying to get as much power as possible from there.

Also, I've yet to read the results of anybody's ANSI standard tests??..hasn't anyone tried to take a 150R racing or trail riding at a location that tests sound yet?? AND, yes, I'm trying to brainstorm a way to post some comparison sound level recordings (video or whatever) the problem is, video cams and such auto adjust their mic levels on the fly to even out the highs and lows and there's no way to disable that feature...I'm thinking of maybe back-to-back recordings using either my iPod?, analog tape recorder?, or maybe even my DVR helmetcam?, so that it will give a good noise level comparison between the exhaust systems.
-Michael

[coffee Get Help Now]

Deilke53 said:

I did get a chance make a few quick runs with the 230f muffler a few weeks ago...

230f slip on with or without the stinger? - the insert held in with a single torx screw.

.

[Deilke53 TT Member]

With. Just out of curiosity we removed it for the very last dyno run...waaaay louder, but (surprise) the graph was absolutely identical.

I explained earlier that I didn't want to modify the 230F muffler internals fo this first attempt...but if I had at least made the diameter reduction more gradual (there are pictures 1 or 2 pages back in this thread) I think the motor would pull a few more revs.

I'm perfectly happy with it as is..but I'm sure it's possible to get a little better performance without adding even one decibel. I have also not messed with the jetting beyond changing the pilot so there is probably an easy gain there too.
-Michael

[coffee Get Help Now]

Deilke53 said:

With. Just out of curiosity we removed it for the very last dyno run...waaaay louder, but (surprise) the graph was absolutely identical.

Don't have a crf150r, but we have a crf230f.

Seems much louder without the stinger - more than the numbers show. Maybe you could shed some light on why, or maybe you are noticing the same phenomena. The "graph" you are talking about - dyno graph or sound level?

==================================================


2005 crf230f, snorkel out, with and without the stinger in the exhaust, 1000+++ miles, A weighted, Radio shack meter that has been tested with rangers meter at an OHV park to be very close to being accurate:

rpm...... dBA*.....dBA**

3000......81.........84
4000......84.........86
4500......85.........87
5000......86.........87
5250......86.........87

* with stinger
** without stinger

It sure sounds a lot louder without the stinger than those #s indicate. Just thought I would pass on the info for those who are interested.

.

[Deilke53 TT Member]

I mean dyno graph...I noticed the same thing seat of the pants on my old 150F. Without the quiet insert and re-jetted with the Honda kit the bike felt no faster, just sounded louder so I changed right back and left it stock. My guess is that it's the small diameter stock system on the your 230F and the sudden diameter reduction at the end of my 150R header that are limiting the power much more than the muffler's final outlet size. The 230F muffler has internal baffles etc instead of a perf tube and packing..so there's quite a bit of volume in there to absorb short throttle bursts before things get backed up even with the quiet insert's very small outlet.

As far as your dBA #s..look at 3Krpm (+3dB), you realize that is twice the sound energy?, (what you're really measuring) and that a jump of just 1dB means it has 1.3 times the sound energy of before no matter what it seems like. That's a big deal, sound energy&intensity determine how far that sound will carry in given conditions, and how many more people it just might piss off along the way.

+1dB=1.3x (=10 to the 0.1st power)
+2dB=1.6x (=10 to the 0.2nd power)
+3dB=2x
+4dB=2.5x
+5dB=3.2x
+6dB=4x
+7dB=5x
+8dB=6.3x
+9dB=7.9x
+10dB=10x
+20dB=100x
+30dB=1000x

I 100% believe that the slight performance gains from louder pipes are not worth the damage they cause to our sport. We can't expect the aftermarkets to give us seriously quiet exhausts until there a lot of demand, but I know we could easily keep 90% of our performance @ only 1/10th of the sound energy output right now with simple tinkering and those numbers would quickly improve with smart fabricators on the task. I really hope that happens before it is too late.
-Michael

[crfklxrider TT Bronze Member]

how about a klx 300r exaust, you have inspired me to try that out since the 300r is only 82 db stock

[Lonewuf TT Newbie]

you little wusseys I can't belive that you can't take the noise. all of you must have sensitive ears.

[crfklxrider TT Bronze Member]

maby some people like to keep the land they ride on you newbie.

[NMdesertRacer TT Addict]

Lonewuf said:

you little wusseys I can't belive that you can't take the noise. all of you must have sensitive ears.

Yeah wait till riding places close down then wonder happened!

[motomom27 TT Member]

not to rain on everyones parade but the 150R / is a RACE bike,R series for Race,F series for Family,when Honda created it they didn't intended it to be trail riden or riden around residents,i'm pretty sure it was intended for the race track to have a thumper enter into a dominant 2-stroke class once again.so if your lookin for a trail bike be smart and try buyin a F series thats ment for trails not a Race bike, and like i said it's ment to take place for the 2-stroke 85-112 , NOT for the 150F thats ment for trails!!!!